The present invention generally relates to a lancet system, and more particularly relates to a lancet system comprising at least one lancet having a lancet tip protected by a sterile protector.
The removal of body fluids such as blood is performed with the aim of subsequent analysis to diagnose illnesses or monitor the state of a patient's metabolism. Diabetics, in particular, remove samples of blood to determine the concentration of blood sugar. In order to remove only small amounts of blood, sharp, sterile lancets are quickly pierced into a patient's fingertip or other body part, for example, by hospital staff or by the patient himself. Lancet systems and other similar devices (for example, blood taking equipment, blood lancet devices, or pricking aids) which extract blood with minimal pain and in a reproducible manner are provided especially in the area of “home-monitoring,” in which lay people carry out simple analyses of their blood.
Lancet tips used for blood extraction are typically sterilized in advance and are stored in a sterile state via a sterile protector (for example, in the form of a cap or pocket) before the lancet is used for a puncturing operation to prevent the tip from being contaminated by the surroundings. Furthermore, measures are frequently taken to ensure that, after a puncturing operation has taken place, the lancet tip is shielded or protected again (for example, by the same cap or pocket) to prevent injury and infections from blood that remains adhered to the lancet tip.
In the case of individual lancets, a sterile protector can be produced, for example, by encapsulating the lancet tip with plastic by injection molding both the lancet body and sterile protector during the same process. Before the lancet is used, the user manually removes the sterile protector upon inserting the lancet body into a pricking aid. In the case of lancets being encased in a magazine, similar sterile protectors are customary in which the lancet is pulled out of the sterile protector, whereby the sterile protector is moved out of the puncture path by a spring force. Relatively complicated mechanisms, such as springs, are integrated into the equipment to carry out this function.
Document WO 01/66010 discloses a lancet system that circumvents the complicated nature of this mechanism by piercing the sterile protector. In particular, document WO 01/66010 relates to a lancet comprising a lancet needle with a tip and a lancet body which completely surrounds the lancet needle at least in the region of the tip. In the region around the tip, the lancet body is composed of an elastic material in which the tip of the lancet needle is embedded. Furthermore, a lancet is disclosed having a lancet needle with a tip and a hollow body which surrounds at least the tip of the lancet needle. The lancet needle is movable in the region of its tip inside the hollow body or housing, and the hollow body or housing is at least partially composed of an elastic material which can be punctured by the tip of the lancet needle during the puncturing operation. Further, and if appropriate, the hollow body or housing closes again after the tip of the lancet needle completes a puncturing operation and is retracted into the hollow body or housing. A disadvantage of this lancet is that the elastic enclosure causes friction along the entire puncture path. Therefore, the drive units or actuators used to move the lancet have to be appropriately dimensioned to carry out the operation. However, enclosing the used lancet tip in this manner is unnecessary in many aspects in which the lancet is held in a magazine or is individually present, because the lancet tip is retracted, for example, into a rigid hollow body or housing and therefore the risk of contaminating the surroundings or risk of injury from the tip is reduced.
U.S. Pat. No. 5,304,192 relates to a lancet device having a lancet needle and a tip which is enclosed by a removable cap. The cap ensures that the lancet tip remains sterile before use. The cap is connected to another component of the lancet device via a breakable connection and is manually twisted off from said component.
U.S. Pat. No. 5,554,166 relates to a blood lancet device with a lancet needle which, in the unused state, is provided with a sterile protective cap. For removal, the sterile protective cap is twisted in such a manner that it breaks off at predetermined tear points.
Manually removing protective caps to release the lancet tip for a puncturing operation is a step to be avoided in a method for removing body fluids, since it complicates the handling of such lancets.